Activity coefficients for NaBr in ethanol-water mixtures at 25�C (original) (raw)
Journal of Electroanalytical Chemistry, 1998
The electrical conductivity of NaBr solutions and the emf of the cell: glass electrode (Na)NaBrAgBrAg in mixtures of water with propan-2-ol in the range 0-80 wt.% have been measured at 298.15 K. The values of limiting molar conductance (\ 0), association constants (K A), and the parameter of distance of ions (R) were obtained with the Fuoss-Justice equation. From the conductivity data obtained, the values of the Walden products (\ 0 p) were also calculated. The values of the Gibbs energy of transfer (Z t G 0) of NaBr from the water to the mixtures of water with propan-2-ol mixtures were obtained from the emf data. The dependencies of viscosity (p), limiting molar conductance (\ 0), Walden products (\ 0 p), association constants (K A) and the Gibbs energy of transfer (Z t G 0) of NaBr versus the mixed solvent composition have been discussed. The obtained results were compared with those obtained earlier for sodium chloride and iodide.
Activity Coefficients for NaCl in Ethanol-Water Mixtures at 25°C
Reccived J anuary 4, J 988; Revised /l.pril J, 1988 /l.clivily coe[ficienl valucs for NaCI in elhanol·waler mixtures cOn/aining 20,40,60, "70, 80 and 90 wcighl % e¡hallol are calculaled from ¡hc ernffor Ihe galvanic cell N a-glass I NaCl (m), 1/ 2 0 (lOO-Y) , ELOII (Y), /l.gCl I/l.g in which ¡hc weigh¡ % of ¡he corresponrlinl? solvenl is indicaled in paren· Ihc.l'cs. 'f'he resulls oblaincd are a!lalyzcd by using differenl Iheorclical models. Chernir:al morlels which lake i!ll o accounl Ihe pre.\'ence 01 ion pairs in solutio!ls 01 high elhwwl conlad are also used. Thcrc is goor! agrccmcnl betwccn Ihe rcsulls oblained from all Ihe m odel.\'.
Activity Coefficients of LiCl in Ethanol−Water Mixtures at 298.15 K
Industrial & Engineering Chemistry Research, 2008
The electromotive force, E, of the cell containing two ion-selective electrodes (ISE) Na-ISE | LiCl(m), ethanol (Y), H 2 O(100-Y) | Cl-ISE has been measured at a temperature of 298.15 K as a function of the weight percentage Y of ethanol in a mixed solvent. Y was varied between 0 and 80% in 20-unit steps, and the molality of the electrolyte (m) was between 0.02 and 4 mol kg -1 , approximately. This electrode system was previously checked and calibrated by measuring the activity coefficients of LiCl in 0, 20, and 40% methanol-water and comparing them with literature values. The values of the standard electromotive force, E 0 (molal scale), were determined using routine methods of extrapolation (Debye-Hückel and Pitzer equations). The results obtained produced good internal consistency within the normal limits of experimental error encountered in these types of measurements. Once E 0 was determined, the mean ionic activity coefficients for LiCl, the free energy of transfer from the water to the alcohol-water mixture, and the primary LiCl hydration number were calculated. The variation of these magnitudes with the composition of the mixture is discussed in terms of the ionsolvent and ion-ion interactions and their changes with the properties of the medium.
Fluid Phase Equilibria, 1995
We have determined the activity coefficients for NaC1 in NaC1 + NaForO + NaAcO + HeO and NaC1 + NaForO + NaPrO + H20 mixtures, and for NaBr in the NaBr + NaForO + NaAcO + H20 mixture (ForO = Formate, AcO = Acetate and PrO = Propionate). The studies were performed by the emf method and at 25 °C. The analysis of the experimental data was accomplished through a Reilly-Wood-Robinson type treatment, by replacing the Friedman parameters by the /-dependence functions defined by the Scatchard, Pitzer and Lim models. The methodology used consisted of introducing the binary interaction parameters, obtained from previous studies of the corresponding ternary mixtures NaX + NaY + H20 (X: CI or Br; Y: ForO, AcO or PRO), into the equations for the quaternary system. In the present paper, the binary interaction parameters corresponding to the mixture NaCI + NaForO + H20 have been more accurately re-determined. The data thus obtained from the use of the different models were compared to each other. The mixing parameters for the NaForO + NaAcO + H20 and NaForO + NaPrO + H20 ternary systems were also determined as ionic strength functions.
Activity Coefficients of NaBF 4 in PEG4000 + Water Mixtures at (288.15, 298.15, and 308.15) K
Journal of Chemical & Engineering Data, 2012
The electromotive force of the cell containing two ion-selective electrodes (ISEs), Na−ISE|NaBF 4 (m), PEG4000 (Y), H 2 O (100 − Y)|BF 4 −ISE, has been measured at temperatures of (288.15, 298.15, and 308.15) K as a function of the weight percentage Y of PEG4000 (poly(ethylene glycol) 4000) in a mixed solvent. Y was varied between (0 and 25) % in five-unit steps, and the molality of the electrolyte (m) was between ca. (0.04 and 7) mol•kg −1. The values of standard electromotive force were determined using routine methods of extrapolation, together with Debye−Huckel and Pitzer equations. The results obtained produced good internal consistency for all of the temperatures studied. Once the standard electromotive force was determined, calculations were made of the mean ionic activity coefficients for NaBF 4 , the Gibbs energy of transfer from the water to the PEG4000−water mixture, and the primary NaBF 4 hydration number.
Fluid Phase Equilibria, 2016
This work purpose is measuring and modeling of the ternary and quaternary systems consist of NaCl and mixed NaClþKCl electrolyte in mixed solvents with different mass fractions (x) of C 2 H 5 OH in H 2 O, where x ¼ 0.10, 0.20, 0.30, 0.40, and 0.50 and in the molality range of (0.0005e3.0) mol kg À1. Based on potentiometric measurement technique, the experimental data are obtained. A cell consists of a Na þglass membrane and Ag/AgCl electrodes and series of electrolyte solutions, used to calculate the activity coefficients at (298.15 ± 0.05) K. The quaternary system of mixed NaCl þ KCl electrolyte in mixed C 2 H 5 OH þ H 2 O solvents is investigated by different molal salt ratios r (r ¼ m NaCl /m KCl ¼ 100, 150, 200 and 250). Modeling is implemented by using particularly, the Pitzer (P) and modified Pitzer by Merida et al. (MP) equations. There is a good agreement between the results obtained from both models. The modified Pitzer approach by Merida et al. permitted the determination of various binary ion-solvent and ternary ion-ion-solvent interaction coefficients which represents complementary data to the usual Pitzer interaction parameters for modeling the named electrolyte systems.
Journal of Molecular Liquids, 2017
In this work, the results of the mean activity coefficient measurements for ionic liquid of 1-propyl-3-methylimidazolium bromide, [PrMIm]Br, in ethanol + water mixtures have been reported using potentiometric measurements at T = (298.2, 308.2 and 318.2) K. The electromotive force (emf) measurements were performed on the galvanic cell of the type: Br-ISE│[PrMIm] (m) ethanol (wt%), H 2 O (1wt)%│[PrMIm] -ISE, in mixed solvent system containing 0, 10, 20, 30% mass fractions of ethanol over ionic strength ranging from 0.0010-2.0000 mol kg -1 . The Pitzer ion-interaction model was used to analyze the activity coefficients for the studied system. The Pitzer ion-interaction parameters (β (0) , β (1) and C ϕ ) were determined and employed to calculate the mean activity coefficients, the osmotic coefficients, and excess Gibbs free energies for the whole series of the studied system.